Key and cylinder locking assembly corresponding to said key

ABSTRACT

A key whose blade includes axially a window forming an opening throughout the thickness of the blade between two opposite faces thereof, and a set of rollers mounted in series along the windows with each roller being mounted freely rotating around a spindle fixed transversal to the window. The key could concern security keys designed to cooperate with a pin tumbler cylinder.

This invention is in the field of security locks in which the aim is tocontrol key duplication. In this context, the invention concerns asecurity key and a locking assembly formed by said key and a lockcylinder with which the key is designed to cooperate.

The locking assembly according to the invention comprises a key and alock cylinder comprising a rotor and a stator, in addition to a set ofpins and counter-pins which, by their respective positioning, enablerotation of the rotor in the stator, so as to proceed to locking orunlocking the lock.

The key according to the invention classically comprises a bow and ablade designed to be inserted into the keyway of the lock cylinder. Keyspreferably used belong to the type of bit keys in which the blade hasimpressions engraved on the faces and the edges to cooperate with thepins in the lock cylinder when the blade is inserted into said lockcylinder. The pins are placed in bores arranged radially in thecylinder, said pins being mobile in translation in their respectivebores and spring-loaded so as to be urged towards the middle of the lockcylinder and to move in the reverse direction when the key is correctlypositioned in the cylinder.

When the appropriate key is inserted, that is, the key whose impressionshave the right dimensions and are correctly placed on the blade, each ofthe pins penetrates into the matching impression recess. The pins arethence placed in an opening position in which they allow the rotor toturn in the stator of the cylinder and thereby unlock the lockingassembly.

The large number of impressions and the way in which they arepositioned, at best rather on the key faces than on the key edges, makeduplication of said keys difficult, thus increasing the security of thelocking assembly.

This invention proposes means to produce the signature pattern ofsecurity keys in a different way. According to an advantageouscharacteristic of the invention, the blade of the key axially comprisesa window that forms an opening through the thickness of the blade fromone face to the opposite one, and at least one roller is mounted on aspindle transversely to the window. The diameter of the roller isdetermined such that when the key is inserted fully into the keyway ofthe lock cylinder, the surface of the roller cooperates with the end ofa pin placed radially in the lock cylinder. Several rollers can bemounted in the window one after the other in succession along the axisof the blade and the successive rollers can have different diameters.

A key is thus proposed which cannot be duplicated by machining,particularly with respect to its signature pattern which is determinedby the rollers. The combination of different positions of rollers havingdifferent diameters provides numerous possibilities for obtaining aunique key signature pattern.

According to a characteristic of the invention, the diameter of theroller can be greater than the thickness of the blade, such that saidroller, when mounted on a spindle fixed in the median plane of the key,projects from both faces of the blade. A security key is thus proposedcomprising elements projecting from the blade faces which are differentfrom the known impressions which are hollowed out as recesses in theblade in the case of usual bit keys, and which nonetheless do notrequire complex machining.

The use of a roller to cooperate with the pins means that a symmetricalkey can easily be produced, that is, a key whose blade can be insertedinto the keyway of the lock cylinder in either direction. Whenimpressions are made on a face or side of the blade, identicalimpressions must be made on the opposite face or side symmetrically withrespect to a point on the median axis of the key at keyway level. Whenusing a roller, the symmetrical configuration can be obtained with easeby centering the roller on the median axis such that there is anidentical protuberance on either side of the key.

Another advantage in using a roller is the ease with which the keyslides into the keyway of the lock cylinder. The roller is mounted torotate freely around its axis, so that when the key is inserted into thekeyway it slides easily over the pins along its pathway. It isunderstood that the key will slide easily both when it is being insertedinto the keyway and when it is being removed from it.

The invention also proposes a locking assembly comprising a key and alock cylinder comprising a rotor and a stator, in addition to a set ofpins and counter-pins which, by their respective positioning, enablerotation of the rotor in the stator for locking or unlocking.

According to an advantageous characteristic of the invention, the pinsare especially arranged to slide radially in the rotor so that each onecorresponds to a roller on the security key when the key is insertedinto the lock cylinder as far as it will go.

In a preferred embodiment according to the invention, a set of rollerscan be arranged axially in series in the window formed in the thicknessof the key blade, the being provided a corresponding set of pins in thelock cylinder, with the number of pins in accordance with the number ofrollers and the space between each pin in their axial arrangement inaccordance with the space between each roller.

It is easily understood that said pins will be driven into the rotor todifferent depths, depending on the diameter of the corresponding roller,when the key is inserted as far as it will go.

The keyway made in the lock cylinder comprises two grooves placedsymmetrically on either side of the keyway so that those rollers thediameter of which is larger than the thickness of the blade (and whichtherefore project beyond the edge of the blade) can pass through thekeyway. The two grooves on either side of the keyway thus form aguide-way for the peripheral surface of the rollers.

The invention will now be more completely described in relation with itspreferred characteristic features and their advantages, referring toFIGS. 1 to 5 in which:

FIG. 1 is a front view of a key according to an embodiment of theinvention which comprises four rollers placed axially in a window formedin the middle of the key blade;

FIG. 2 is a bottom view of the key illustrated in FIG. 1;

FIG. 3 is a cross-section of the security cylinder corresponding to thekey illustrated in FIGS. 1 and 2;

FIG. 4 is a schematic drawing illustrating the cooperation of a keyaccording to the invention with the corresponding security cylinder,with the cylinder only being represented partially;

and FIG. 5 is a cross-section of the assembly formed by the key and pincylinder as illustrated in FIG. 4 in the plane of the key.

As illustrated in FIG. 1, the key comprises a bow 2, partly visible, anda blade 4 designed to be inserted into the lock cylinder. Anintermediate neck 6 is formed between the bow and the blade. At itsjunction with the blade, it has two shoulders that prevent the key fromgoing any further when it is inserted into the lock cylinder.

Blade 4 has a flat shape, here of rectangular section, and comprises afree front end 8 placed axially opposite the neck, cut to form a point.The blade has two edges 10 and 12 and two main faces 14 and 16.

According to the invention, the blade has a window 18 which forms anopening through the key from one side to the other, extending axiallyand centrally along the blade, that is, at an equal distance from theedges. It can be understood that, in this arrangement, the median axisof the window is the same as that of the median axis of the blade.

Rollers 20 are placed in the window. They are each mounted to rotatefreely around a spindle 22 placed transversely in relation to thewindow. In the illustrated example, there are four rollers, placedsuccessively along the window.

Each of the rotating spindles is mounted in a blind hole which extendstransversely from one of the blade edges at an equal distance from bothfaces. The rotating spindle is inserted into the blind hole via saidedge until it comes up against the bottom of the blind hole. Said holehas a depth such that the bottom of the blind hole is situatedtransversely outside the window, such that the spindle inserted into thehole passes through the window.

Each roller is mounted to rotate freely around its spindle which isplaced transversely in relation to the median blade axis, such that eachroller is designed to turn in a direction parallel to said median bladeaxis, which corresponds to the direction in which the blade is insertedinto the lock cylinder. As described below, this facilitates insertionand removal of the key with respect to the lock cylinder. The rollerhere is in the form of a straight cylindrical roller, it beingunderstood that it could alternately take other forms provided itfulfills its role of cooperation with the corresponding pin of the lockcylinder and enables the roller to slide past the pins when the key isinserted into the keyway. The straight cylindrical form is the mostsuited to cooperate with the end of the pins when they are directedradially in the rotor at an angle with respect to the generatrix of thecylindrical circumference of the roller.

The rollers can be of different diameters. Depending on their diameter,they may or may not project beyond the blade. Thus, a roller willproject beyond the blade when its diameter is greater than the thicknessof the blade, whereas it will be entirely contained within the thicknessof the blade when its diameter is less than that of the blade. It isunderstood that since the rotating spindle is inserted into a blind holewhich extends at an equal distance from the blade faces, the roller willprotrude the same distance beyond each blade face.

As shown in FIG. 2, the center-to-center distance between twoneighboring rollers remains the same along the entire window. Thatcenter-to-center distance(marked d in the figure) is specified to tworollers can be placed side by side without touching each other, whatevertheir diameter.

The number of rollers and the different available sizes of each roller,results in a very large number of possible combinations, which offers avery wide signature pattern choice for this type of key.

The blade can also comprise impressions 24 (as shown in FIG. 4) engravedon the key faces or on the key edges so as to form recesses of differentdimensions and depths, as would be known from previous constructions.Said impressions may have cup forms, drilled to various depths withrespect to the plane of one of the blade faces. In the particular casedescribed, the impressions are distributed symmetrically with respect tothe median axis so as to make the key reversible, that is, to enable theblade to be inserted into the keyway indifferently in one direction orin the other. It can understood that said impressions are positioned totake into account the presence of the window on either side of the keyand the presence of blind holes through the edges.

We are now going to describe a process to construct a key as describedpreviously. The manufacturing process comprises three distinctsuccessive steps, that is, a first machining step during which the basicelements of the key are made, a second mounting step in which a keysignature pattern according to the invention, specific in that itcorresponds to a lock cylinder, is created by assembling the differentcomponents of the corresponding key in a pre-determined configuration,and a third machining step in which additional operations are carriedout to form the impressions on the blade.

The first step consists in machining the window to be formed in the keyand the blind holes. The result is a standard key model, different fromregular keys in that it has a window, but which can be used fordifferent key models according to the invention.

The spindles are also made during this first step and are designed to beinserted into the blind holes during mounting. Each of the spindles ismachined in the usual way to obtain a pre-determined diameter andlength. Finally, the rollers are made with different diameters so thatthey can be adapted to the specific needs of each of key.

The key bittings are obtained in the second step by mounting at leastone roller of specific diameter in the window. The number of rollers,their respective diameters, and their arrangement from one side of thewindow to the other, offer a large number of signature patterns whichgive the key its uniqueness and traceability.

During mounting of each of the rollers, the roller is held in place inthe window at the level of one of the blind holes while inserting arotating spindle into said blind hole so that it passes through the holeengraved in the roller. When the spindle is pressed up against thebottom of the blind hole, the spindle is prevented from moving bycrushing the edge of the blind hole receiving the spindle in order toreduce the opening diameter of the hole and prevent the spindle frommoving. Said fixation by crushing the edges has the advantage ofpreventing the key from being dismounted.

The signature pattern which is specific to said key and makes it uniqueand which therefore contributes to the security of the locking assemblyit is a part of, is also obtained by machining impressions during thethird step. According to the invention, said impressions are machinedafter forming the window and holes so that the impressions will bepositioned around them. The layout of the impressions is specific to thekey and corresponds to a specific layout of the cooperating elementscomprised in the lock cylinder with which the key matches.

As illustrated in FIGS. 3 to 5, a key according to the invention isdesigned to cooperate with a lock cylinder 26 specific in that itcomprises a series of pins designed to cooperate with the series ofrollers.

The cylinder comprises a rotor 28 designed to turn inside a stator 30.The rotor has a keyway 45 into which the key is designed to be inserted.Said keyway has two grooves 46, positioned symmetrically on either sideof the keyway, approximately in the middle. The keyway is staggered withrespect to the axis of the cylinder along one of the diameters of thecylinder, as seen in FIG. 3.

A set of bores 32 is made in the cylinder, extending radially from theoutside of the stator to the keyway of the rotor, comprising two partsmachined in the rotor and stator respectively. An assembly formed by apin 34 and a counter-pin 36, independent of each other, is installed ineach of the radial bores and pushed towards the inside of the cylinderby a spring 38, supported by the counter-pin. The bottom of the borecomprises a shoulder that enables a pin head to pass through so that itis in contact with the key and prevents the body of the pin going anyfurther by the action of the spring. The pin head, opposite thecounter-pin, has a dome-shaped end, approximately the shape of aspherical dome. This shape is particularly appropriate for the pins totake up position opposite the circumference of the rollers mounted inthe axis of the key.

In the rest position of the cylinder, that is, in the position it takesup naturally when the key is not inserted in the lock cylinder, theproximal bore in the rotor is positioned at an angle in the extension ofthe distal bore in the stator, such that the pin and its correspondingcounter-pin can slide along the bore formed by the two parts combined.Furthermore, the pin is pushed into the rotor by the spring supported bythe counter-pin, such that, in the rest position, without a key insertedinto the cylinder, the counter-pin extends partly into the rotor andpartly into the stator, preventing the rotor from rotating in relationto the stator.

As illustrated, the pin and counter-pin are both dissociable elementsone of which has a convex contact face 40 and the other a concavecontact face 42. Said faces have a radius of curvature approximatelyequal to the radius of the rotor. The rotor is thus designed to turninside the stator when the contact faces of the pin and the counter-pinare positioned at the junction between the rotor and the stator.

It is understood that the movement of the rotor in the stator will onlyoccur when the pins are placed at the correct height in their radialbore, so that only the pins are in the rotor and only the counter-pinsare in the stator.

To achieve this, the correct key must be used, that is, the key whoseimpressions and rollers are of the right dimension and are correctlyplaced on the blade, inserted correctly until it comes up against neck 6in the cylinder.

During insertion, the main action of the blade is to push the pin headstowards the stator, therefore compressing the spring via thecounter-pin. When the key is in place, the different pins are pushed bythe counter-pins to the bottom of the corresponding impressions and ifthe impression is in the correct place and of correct dimension, theassembly formed by the pin and counter-pin is adjusted in radialposition so that the opposite faces are located at the junction betweenthe rotor and the stator, which can turn freely.

Impressions of different depths and rollers of different diameters willbe made to obtain a unique key that corresponds to the dimensions of thepins placed in a unique manner in the lock cylinder.

For example, on FIG. 3, a dotted line is used to indicate the shape ofthe impressions that would enable the lock to be opened and a solid lineto indicate the actual shape of the key. It can be seen that a set ofpins are arranged to be activated by a set of impressions made on one ofthe edges and that the other pins are arranged so as to be activated bya set of impressions made on one of the faces. As illustrated, dependingon whether an impression is too deep or is absent at the required place,the assembly formed by a pin and counter-pin will be driven more or lessinto the bore and the pin or the counter-pin then prevents the rotorfrom turning.

The invention also covers a not represented embodiment in which at leastsome of the rollers have an annular groove around the circumference ofthe roller. The groove can advantageously have an asymmetrical hollowprofile like the other impressions on the key to cooperate as well aspossible with pins that move into them at an angle. It should be notedthat the groove is perfectly compatible with the role of guide roller tofacilitate insertion of the key until it cooperates with the cylinder.For this the groove needs to be formed in a central part of the roller,leaving the original cylindrical part on either side.

According to the invention, the lock cylinder comprises a specificseries of pins, in which each of the pins is designed to cooperate withone of the rollers on the key previously described. The set of bores 33corresponding to this specific series extends along an inclined axis (asshown in FIGS. 3 and 4) with respect to the axis perpendicular to therotational axis of the rollers such that it points to the rotationalaxis of the rotor. In this way, the pins and counter-pins designed toslide in said bores can be placed on either side of the curved junctionplane between the rotor and the stator.

As can be seen on FIGS. 4 and 5, the number of rollers will be at leastequivalent to the number of pins placed in series in the cylinderspecifically to be activated by said rollers. The sizes of the rollersare chosen according to the shape and dimension of the pins so that thepins are correctly retracted when the key is inserted into the keyway asfar as it will go in order to cause rotation of the rotor.

It is understood that the diameter of the rollers is chosen according tothe dimension of the pins. In the rest position of the lock cylinder,certain pins can be arranged so as to project further into the keywaythan the other pins, and said pins are made to correspond with therollers whose diameter is smaller than the others. Advantageously, thefact that each of the rollers is mounted to rotate freely around itsaxis enables the key to be easily inserted without striking the pinheads projecting into the keyway. A large diameter roller radiallypushes said pin heads out of the way without difficulty until it comesinto contact with its corresponding pin head when the key is insertedinto the lock cylinder as far as it will go, and the pin heads that werepushed away radially during insertion of the key return to theiroriginal position under the action of the corresponding springs afterthe large diameter roller has passed.

When the key is inserted into the keyway of the lock cylinder, the largediameter rollers which project on either side of the blade slide intothe grooves formed symmetrically on either side of the keyway. Thegrooves are dimensioned to let the largest diameter roller pass throughand they are useful in centering and guiding the key when being enteredin the cylinder.

The above description clearly explains how the invention enables itsobjectives to be achieved, particularly its security objectives, byproposing a key whose duplication is impossible without having a blankkey with rollers. The context is that of a security key to which asignature pattern is to be given. According to the invention, saidsignature pattern is obtained by added elements that can form eitherembossed areas or hollowed depressions whereas previous keys would leadonly to vary the depth of depressed impressions. Providing for addedelements projecting out of the blade beyond its faces also enables thekey to be guided during its insertion into the lock cylinder. The addedelement has a cylindrical or spherical shape and is mountedrotationally, which has the advantage of minimizing the friction againstthe pins that project into the keyway when the key is inserted into thelock cylinder. Each roller is arranged so that it can turn round in adirection parallel to the direction in which the blade is inserted intothe lock cylinder, which facilitates the displacement of the key in thelock cylinder, during both insertion and removal, since the key is freeto rotate. The rollers cylindrical or spherical shape also facilitatesthe design of a reversible key.

Furthermore, the fact that the signature pattern of the key is obtainedthrough the combination of added elements means that production of thebasic elements of the key can be standardized while enabling duplicationof the keys to be controlled, due to the fact that the assembly of therollers in the key in the production unit cannot be changed subsequentlyand to the many possible combinations of said elements.

1. Key whose blade comprises axially a window which forms an openingthrough the thickness of the blade from one side to the other and inwhich at least one roller is mounted to rotate freely around a fixedspindle mounted transversely to the window in the thickness of the key.2. Key according to claim 1, wherein the several rollers are arrangedsuccessively one after the other in the window, along the axis of thekey blade.
 3. Key according to claim 2, wherein the rollers havedifferent diameters.
 4. Key according to claim 3, wherein the diameterof the roller is greater than the thickness of the blade such that theroller, mounted rotationally around a spindle in the median plane of thekey, projects on either side of the blade faces.
 5. Locking assemblycomprising a key according to claim 1 and a lock cylinder comprising arotor and a stator, in addition to a set of pins and counter pins which,by their respective positioning, enable rotation of the rotor in thestator to be locked or unlocked, wherein one of the pins is arranged toslide radially in the rotor so that it corresponds to a roller when thekey is inserted into the lock cylinder.
 6. Locking assembly according toclaim 5, wherein the diameter of the roller is determined such that whenthe key is inserted into the lock cylinder, the surface of the rollerwill cooperate with the end of a pin.
 7. Locking assembly according toclaim 6, wherein the rollers are arranged axially in series in thewindow formed in the thickness of the blade and that a corresponding setof pins is arranged in the lock cylinder such that the number of pins isequivalent to the number of rollers and the space between each pin intheir axial arrangement is equivalent to the space between each of therollers.
 8. Locking assembly according to claim 6, wherein the lockcylinder comprises a keyway for insertion of the key, with said keywaycomprising two grooves placed symmetrically on either side of the keywayso that rollers which are of larger diameter than the thickness of theblade can pass through the keyway.
 9. Locking assembly according toclaim 5, wherein at least one roller has an annular groove around itscircumference to cooperate with the end of a pin.